Relation of Dietary Acetic and Butyric Acids to Intake, Digestibility, Lactation Performance, and Ruminal and Blood Levels of Certain Metabolites

Abstract

The hypothesis was tested that acetic and butyric acids are related to the lower dry matter intake and superior efficiency which usually results from feeding lactating cows silage rations compared to hay. Voluntary intake of dry matter was not affected by 2% acetic, 1% butyric, or a combination of these acids added to a hayconcentrate ration. However, a mixture of 4% acetic and 2% butyric acids appeared to cause nasal irritation and reduced intake. Milk yield and milk fat content were not appreciably affected by treatments. Although acetic acid increased energy digestibility, none of the treatments improved efficiency of energy utilization. Rumen concentration of acetic and butyric acids was higher, and propionic acid lower, for the supplemented rations. Blood acetic and butyric acids were elevated by the acetic and the acetic-butyric acid supplements. These results generally did not support the hypothesis that acetic and butyric acids increased efficiency of dry matter utilization. © 1967, American Dairy Science Association. All rights reserved.